1. Field of the Invention
This invention relates to processors and, more particularly, to implementation of hash algorithms.
2. Description of the Related Art
Verifying the integrity of data, such as file data, program code, or communications data, for example, has become an increasing concern as electronic commerce and communication proliferates. For example, data integrity is continually under threat as new forms of computer viruses and other malware emerge. Moreover, stored data is subject to corruption due to unintentional events such as hardware failure, data communication errors, and the like. Compromised or corrupted data may result in undesirable consequences ranging from transient application malfunction to widespread data loss, data theft, or total system failure.
To provide a means for ascertaining data integrity, various types of hash algorithms have been developed. Generally speaking, a hash algorithm may be configured to generate a condensed representation, or hash value, of an input stream of data. For typical hash algorithms, any change to the input data stream may result in differing hash values. Thus, if a given computed hash value of a data stream does not match an earlier-computed hash value of that data stream, the integrity of the data stream may have been compromised. As an example, “known good” hash values of a data stream may be computed before the data stream is conveyed via an insecure medium and conveyed along with the data stream. At the receiving end, the hash value of the received data stream may be computed and compared against the received hash value to provide a data integrity check.
Numerous different types of hash algorithms have been defined, and increasingly sophisticated hash algorithms continue to be developed. To improve execution performance of such algorithms, they may be implemented within processor hardware. However, using individual logical instructions that are defined within the ISA can be problematic, as it is difficult to break down hash algorithms into their constituent instructions.